EVERYDAY SCIENCE

Detailed explanation-1: -pulley: A simple machine consisting of a grooved circular wheel which guides a rope, cable or chain. This machine is primarily used to lift heavy loads along a direct vertical path.

Detailed explanation-2: -A screw is an inclined plane wrapped around a cylinder. Screws are used to hold things together, make holes, and move air and water (in the case of propellers) as well as help lift heavy objects.

Detailed explanation-3: -A pulley is a simple machine that consists of a rope and grooved wheel. The rope fits into the groove in the wheel, and pulling on the rope turns the wheel. Pulleys are generally used to lift objects, especially heavy objects. The object lifted by a pulley is called the load.

Detailed explanation-4: -Movable pulleys are different types of pulleys as they move with the object and unlike the fixed pulley; they need little effort to lift the heavy objects. They multiply the effort made on them. The drawback of using these pulleys is that they do not change the direction of the object.